1. Technical Field
The present invention is directed toward window operators, and more particularly toward an improved track for use with window operators having a roller controlling movement of the sash.
2. Background Art
Window operators are well known in the art for controlling movement of window sashes relative to their frames. Operators for casement type windows, in which the sash is pivoted open or closed about an axis on one side of the sash are also known. Examples of such operators are shown, for example, in U.S. Pat. No. (Stavenau et al.) 2,775,446, U.S. Pat. No. (Stavenau et al.) 2,824,735, U.S. Pat. No. (Stavenau) 2,977,810, U.S. Pat. No. (Stavenau) 3,032,330, U.S. Pat. No. (Stavenau) 3,064,965, U.S. Pat. No. (Stavenau) 3,064,966, U.S. Pat. No. (Stavenau) 3,214,157, U.S. Pat. No. (Stavenau) 3,258,874, U.S. Pat. No. (Van Klompenburg et al.) 4,241,541, U.S. Pat. No. (Peterson et al.) 4,253,276, U.S. Pat. No. (Erdman et al.) 4,266,371, U.S. Pat. No. (Nelson) 4,305,228, U.S. Pat. No. (Vetter) 4,497,135, U.S. Pat. No. (Vetter) 4,617,758, U.S. Pat. No. (Allen) 4,823,508, U.S. Pat. No. (Tucker) 4,840,075, U.S. Pat. No. (Nolte et al.) 4,843,703, U.S. Pat. No. (Nolte et al.) 4,845,830, U.S. Pat. No. (Tucker) 4,894,902, U.S. Pat. No. (Tucker et al) 4,937,976, U.S. Pat. No. (Nolte et al.) 4,938,086, U.S. Pat. No. (Berner et al.) 4,945,678, U.S. Pat. No. (Tucker et al.) 5,054,239, U.S. Pat. No. (Tucker et al.) 5,152,103, U.S. Pat. No. (Vetter et al.) 5,199,216, U.S. Pat. No. (Tucker et al.) Re. 34,230, U.S. Pat. No. (Nolte et al.) 5,272,837, and U.S. Pat. No. (Midas) 5,313,737.
With certain of the window operators disclosed in the above patents, such as U.S. Pat. No. (Peterson et al.) 4,253,276, U.S. Pat. No. (Erdman et al.) 4,266,371, U.S. Pat. No. (Tucker) 4,840,075, U.S. Pat. No. (Vetter et al.) 5,199,216, and U.S. Pat. No. (Midas) 5,313,737 (commonly referred to as single arm or double arm operators), movement of the window sash is controlled through an arm having a roller on its end which travels in a track secured to the sash, whereby pivoting of the arm results in the roller acting on the track to correspondingly move the sash. Of course, it will be appreciated that smooth operation of such window operators requires smooth operation of the rollers. However, such smooth operation can be difficult to achieve, particularly over the long expected life of such operators, due to the great stresses which the rollers inevitably face, not only when opening and closing the sash but also when holding the controlled sash in a particular position notwithstanding constantly changing loads (due to changing winds).
In many installations, particularly in areas subject to high winds, it is desirable to include stops to protect against window sash damage which could result from an open window being caught by a gust of wind and violently thrown further open beyond the limits of the sash supporting structure. For example, some hinges are provided with stops which limit the amount which they can be opened. U.S. Pat. No. (Pettit et al.) 4,932,695 shows a support arm with a passive lock system adapted to prevent wind damage and used in conjunction with a hinge. Limit devices completely separate from the operators and hinges have also been used to guard against such damage. Unfortunately, such devices can introduce a relatively high additional cost for the hardware on the window, can involve additional time and therefore added expense in assembling the windows, and in some cases require additional space in the assembled window (which is completely contrary to the desire to minimize the intrusion of hardware on the window opening).
The present invention is directed toward overcoming one or more of the problems set forth above.